In the PRIME study, AVP-923 treated patients experienced levels of pain reduction commensurate with those observed in similar studies and the improvement in pain scores from baseline reached statistical significance; however, there was no difference between the treatment arms and placebo. Avanir believes that a higher than expected placebo response negatively impacted the study results. AVP-923 was generally safe and well tolerated.

Avanir plans to review the detailed data from the PRIME study in conjunction with previously generated data in diabetic peripheral neuropathic pain to determine next steps for the development of AVP-923 in neuropathic pain.

About the PRIME StudyThe objectives of the PRIME (Pain Research In Multiple sclErosis) study were to evaluate the safety, tolerability, and efficacy of AVP-923 for the treatment of central neuropathic pain in patients with multiple sclerosis. The trial was a multicenter, randomized, double-blind, placebo-controlled, 4-arm parallel group study that enrolled 209 patients. Eligible patients received one of three dose levels of AVP-923 containing either 45mg DM/10 mg Q, 30mg DM/10mg Q, 20mg DM/10mg Q or placebo, daily for 12 weeks. The primary efficacy endpoint was measured based on the Numeric Pain Rating Scale (PRS) as recorded in patient diaries. Primary analysis of this endpoint correlated pain scores with dextromethorphan plasma concentrations. Secondary analysis correlated pain scores with AVP-923 dose and also compared pain scores for those treated with placebo versus drug in each dose group.

About AVP-923AVP-923 is a combination of two well-characterized compounds, the active CNS ingredient dextromethorphan hydrobromide (an uncompetitive NMDA receptor antagonist and sigma-1 receptor agonist) plus low-dose quinidine sulfate (a CYP2D6 enzyme inhibitor), which serves to increase the bioavailability of dextromethorphan. AVP-923 is being studied in several ongoing company sponsored Phase II clinical trials including agitation in Alzheimer's disease, levodopa-induced dyskinesia in Parkinson's disease and several investigator initiated studies. AVP-923 can interact with other medications and should not be used in patients taking certain drugs. AVP-923 can cause serious side effects and should not be used in patients with specific cardiovascular risk factors. These are not all the risks from use of AVP-923. AVP-923 is an investigational drug not approved by the FDA.

About Avanir Pharmaceuticals, Inc.Avanir Pharmaceuticals, Inc. is a biopharmaceutical company focused on bringing innovative medicines to patients with central nervous system disorders of high unmet medical need. As part of our commitment, we have extensively invested in our pipeline and are dedicated to advancing medicines that can substantially improve the lives of patients and their loved ones. For more information about Avanir, please visit www.avanir.com.

AVANIR® is a trademark or registered trademark of Avanir Pharmaceuticals, Inc. in the United States and other countries.

Forward Looking StatementsExcept for the historical information contained herein, the matters set forth in this press release, including statements regarding Avanir's plans, potential opportunities, financial or other expectations, projections, goals objectives, milestones, strategies, market growth, timelines, legal matters, product pipeline, clinical studies, product development and the potential benefits of its commercialized products and products under development are forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially, including the risks and uncertainties associated with, the market demand for and acceptance of Avanir's products domestically and internationally, research, development and commercialization of new products domestically and internationally, including the risks and uncertainties associated with meeting the objectives of the study of AVP-786, and AVP-923, including, but not limited to, risks relating to the successful development of these investigational drugs, delays or failures in enrollment, or delays in the release of study results, obtaining additional indications for commercially marketed products domestically and internationally, obtaining and maintaining regulatory approvals domestically and internationally, and other risks detailed from time to time in the Company's most recent Annual Report on Form 10-K and other documents subsequently filed with or furnished to the Securities and Exchange Commission. These forward-looking statements are based on current information that may change and you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement, and the Company undertakes no obligation to revise or update any forward-looking statement to reflect events or circumstances after the issuance of this press release.